The rails of a railroad track are usually secured to cross ties by spikes driven into tie plates, with the tie plates located between the rail and the tie, and the head of the spike overlapping the bottom of the rail. The tie plates block lateral movement of the rails. Anchors are attached to the rail on either side of the tie to secure the rail against longitudinal movement.
Railroad ties occasionally must be replaced due to wear. After a tie is replaced, tie plates must be provided between the rail and the tie so that the rail may be properly secured to the tie.
Several references propose various systems for use in replacing tie plates. For example, U.S. Pat. No. 4,280,613, issued to J. K. Stewart on Jul. 28, 1981, describes a tie plate conveying and orienting system.
U.S. Pat. No. 4,770,103, issued to F. Allmer on Sep. 13, 1988, describes a rail clamp. The rail clamp includes a pair of line-up wheels for engaging the inside edges of the rails. A pair of pivoting clamping arms, with each clamping arm having a disk rotatably mounted to its end, engages the outside edge of each rail, just below the rail's ball. Movement of the clamping arms is controlled by hydraulic cylinders. Additionally, a stabilizer cylinder connecting a bridge crossing the chassis to the rail lifting assembly may either permit the rail lifting assembly to float to correspond with the rails, or may be locked in position.
U.S. Pat. No. 4,733,614, issued to G. Mohr et al. on Mar. 29, 1988, describes a machine for repairing a railway track. The machine includes a main chassis having various devices for repairing a railway, mounted on a chain drive under a railway vehicle. A counter weight mounted to the chain drive, moving the opposite direction, counters the effects of inertia.
U.S. Pat. No. 4,942,822, issued to D. J. Cotic on Jul. 24, 1990, describes an apparatus and method for automatically setting rail tie plates. The apparatus includes a frame having a ramp thereon. The ramp stores the tie plates, and includes a control mechanism for releasing them one at a time into a plate pocket. A reciprocated pusher then moves the plate from the plate pocket to its position on the tie.
U.S. Pat. No. 5,067,412, issued to J. Theurer et al. on Nov. 26, 1991, describes a tie plate-inserting machine. The front of the machine includes a crane broom with a tie plate-collecting magnet. A funnel adjacent to the crane leads to a conveyer, which terminates above a sorting table. A roller conveyer conveys ties from the sorter to a magazine. The magazine moves between a level position for receiving tie plates from the sorting table, and a lower position for dispensing the tie. The machine includes a tie plate-inserting arm slidably supported by a guide rod, for pushing the—tie plates from the magazine to their position below the rail. A lifting roller pivots between a raised position and a lowered position for permitting tie plates to be pushed thereon from the magazine to their final position below the rail.
U.S. Pat. No. 5,193,461, issued to J. Theurer et al. on Mar. 16, 1993, describes a tie exchange means for both removing ties and inserting new ties. The tie exchange machine may move longitudinally along a guide track. A scarifier and track-lifting device are included. A mobile tie transporting crane may move towards or away from the tie exchange device, for transporting either new ties to be installed or old ties which have been removed. The tie-depositing device is a vertically adjustable forklift.
U.S. Pat. No. 5,305,692, issued to H. Madison et al. on Apr. 26, 1994, and assigned to Harsco Corporation, describes a tie exchanger mounted on a truck. The tie exchanger has a rail clamp table having rail clamps and a boom. The boom includes a tie clamp, and may pivot around the vertical axis to insert ties from either side of the tracks.
U.S. Pat. No. 5,331,899, issued to J. D. Holley on Jul. 26, 1994, describes a tie plate installer and remover using a magnetic wheel to insert or remove a tie plate. The tie plate installer includes a tie magazine from which tie plates are dropped into a shoot leading to the magnetic wheel, which then carries the tie plate to a position on the tie adjacent to its final location under the rail, and finally pushes it under the rail.
U.S. Pat. No. 5,419,259, issued to J. Theurer et al. on May 30, 1995, describes a ballast stabilizer. The ballast stabilizer has a rail clamp including a roller for engaging the rail's ball, mounted on an arm secured at its other end to a lever. The opposite arm of the lever is secured to a hydraulic cylinder, so that extending the cylinder pushes inward on the clamp arm. A pair of vertical inner wheels are pushed against the gauge side of the rail's ball by hydraulic cylinders. A shaking apparatus vibrates the machine parallel to the ties.
U.S. Pat. No. 5,722,325, issued to K. E. Glomski et al. on Mar. 3, 1998, describes a tie replacement apparatus including drip elements for holding a tie plate in place while the tie underneath is replaced.
U.S. Pat. No. 5,839,377, issued to D. M. Brenny et al. on Nov. 24, 1998, describes a machine for installing and removing elastic rail clips of the type used for fastening rails to concrete or wooden ties.
U.S. Pat. No. 6,170,401, issued to R. Miller et al. on Jan. 9, 2001, describes a rail vehicle for collection and distribution of railroad cross ties.
When replacing tie plates, it is useful to position the tie plates near the section of track where the plates will be used to secure the rail to the ties. More specifically, it would be helpful to be able to automatically or semi-automatically place a tie plate at the respective ends of a railroad tie to which a section of rail is going to be attached. Furthermore, it is desirable to be able to easily manipulate and move an apparatus which could automate the tie-placement system and to tie such an apparatus into an existing hi-rail truck or other rail-vehicle system. Accordingly, a railway tie placement apparatus and method incorporating these features is desired.